KANDAHAR, AFGHANISTAN - With 2,000-pound bombs, 12,000 troops, and one illiterate but charismatic Afghan border police commander, the American military has forced insurgents to retreat from key parts of this strategically vital region, according to U.S. and Afghan commanders.

The developments are far from decisive, but senior military leaders believe they have made progress on the western outskirts of Kandahar city and in the pomegranate orchards of the Argandab valley. The ground remains treacherous, seeded with bombs that reverberate daily through the city.

The Taliban departure from some areas could be a strategic response to an operation NATO has trumpeted for months. Or insurgents could be lying low, developing new avenues of attack. NATO forces have cleared villages before, including in Kandahar province, and failed to hold them. Whether insurgents can be kept away this time, or prevented from grabbing new parts of the city or its surroundings, remains to be seen.

The most unexpected, and potentially risky, aspect of NATO's resurgence is Abdul Razziq, the 32-year-old police colonel best known for allegations of pocketing millions of dollars in illegal customs dues, who has left the border to lead hundreds of his militiamen into Taliban-held villages that have bedeviled NATO troops for years.

Behind Razziq's hardened fighters - who possess a local knowledge that police officers and soldiers from Afghanistan's national security forces cannot match - American soldiers have taken back territory previously out of reach. He's led clearing operations in all of the areas central to the American campaign here - Panjwayi, Zhari, Argandab and Kandahar city - and has captured hundreds of Taliban fighters.

"He's like a folk hero now," said Col. Jeffrey Martindale, who commands an American army brigade in Kandahar. "The Taliban fear him."

Afghans who live in these areas, and have witnessed earlier clearing operations give way to Taliban comebacks, often do not share the U.S. military's optimism. And some believe insurgents may be moving into the city to avoid U.S. troops on the periphery. "Security in the city is now drastically worse," said Samsor Afghan, 27, a university student who runs a computer software store downtown, across the street from where a suicide bomber attacked the day before. "The Taliban are everywhere. We don't feel safe even inside the city."

American commanders have nevertheless been buoyed by changes in areas where the bulk of their forces are located. Among the shifts is what they describe as a new assertiveness from Afghan security forces, which now outnumber NATO troops in this operation.

A late-night call

Officers trace the change to one night in mid-August, when Kandahar governor Toryalai Wesa called President Hamid Karzai to report that Taliban forces were blocking a road and searching cars in Malajat, an insurgent stronghold in western Kandahar city.

"Could you, Mr. President, order NATO to come and help us?" Wesa asked, according to an Afghan official present in the palace.

"Shame on you," Karzai replied.

Karzai had recently issued a decree instructing governors to act as the commander of all Afghan security forces in their provinces. He told Wesa to assemble his own force and respond. "Go after them. Don't wait for NATO," he said.